$ { {-2} \times \left[\begin{array}{rr}{0} & {0} \\ {4} & {-1}\end{array}\right] = {?} } $
Explanation: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rr}{-2}\times{0} & {-2}\times{0} \\ {-2}\times{4} & {-2}\times{-1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{0} & {0} \\ {-8} & {2}\end{array}\right]}$